1. Field of the Invention
The present invention generally relates to automatic musical performance apparatuses for recording musical performance data onto a recording medium such as a magnetic disk and for reproducing the musical performance data from the recording medium by use of a buffer memory such as a random access memory (RAM), and more particularly to an automatic musical performance apparatus for efficiently controlling a data transfer between the recording medium and the buffer memory so as to shorten a wait time before the musical performance data can be reproduced.
2. Prior Art
Conventionally, automatic musical performance apparatuses for using a buffer memory and a floppy disk are well known. In a first type of automatic musical performance apparatuses, musical performance data (or musical performance information) are produced by playing an electronic musical instrument, and this musical performance data are passed through the buffer memory and are stored in the floppy disk which is later read for playing such automatic musical performance apparatuses. When the conventional automatic musical performance apparatus is played, a predetermined quantity of the musical performance data is pre-transferred to the buffer memory, and thereafter, remaining musical performance data are sequentially transferred from the floppy disk to the buffer memory while the pre-transferred musical performance data are sequentially read from the buffer memory and are reproduced. Hence, the musical tone corresponding to the reproduced musical performance data is generated. In this conventional automatic musical performance apparatus, a wait time is inevitably generated between a start time for playing the automatic musical performance apparatus and another start time for reproducing the musical performance data.
In a second type of conventional automatic musical performance apparatus, all of the musical performance data stored in the floppy disk are transferred to the buffer memory, and thereafter, the musical performance data are read from the buffer memory and are reproduced.
The first type of conventional automatic musical performance apparatus is superior to second type of conventional automatic musical performance apparatus in that the wait time becomes shorter and the storage of the buffer memory becomes smaller.
However, the predetermined quantity of the musical performance data described above is set constant throughout all tunes which are played in the first type of conventional automatic musical performance apparatus. Hence, the first type of conventional automatic musical performance apparatus suffers a disadvantage in that the wait time becomes longer when the tunes with less tune data are played.
In this case, an average transfer speed Va is defined by a formula Va=E/T, where E denotes a number of events such as a key-on and a key-off occurred at playing and T denotes a time required for playing. The first type of conventional automatic musical performance apparatus sets the predetermined quantity of the musical performance data to a relatively large quantity in order to play a tune having a large average transfer speed Va. Hence, the wait time becomes longer when a tune having small average transfer speed Va is played.